A power plug includes a base, an upper cover attached to the base, a base-side cover adjacent the base and removeably attached to the upper cover, an output cord, a leakage current detection and protection circuit for detecting a leakage current in the output cord, and an electrical connection mechanism for electrically connecting and disconnecting an input side and an output of the power plug. The leakage current detection and protection circuit and the electrical connection mechanism are attached to the base and disposed substantially within a space enclosed by the base and the upper cover. A plurality of connecting ends of the circuit extend from the space enclosed by the base and the upper cover into a space enclosed by the base-side cover and the upper cover. Wires of the output cord are connected to the connecting ends, respectively.